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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '750c78b9d6a0a2f9fd4cec3188dad2e3c1814d0e77592b10b5f0d5e6c141fa18' 
  AND token = 'LkEu+3coqFiNTHvjMo7EnH59JWgxd8009tMHSDcJDWs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}