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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e0ec5b16e27ebc1965b280773d3136f31115e8e0eb3e6d256436f1c5a6e2c66' 
  AND token = 'kJ+Ys3ahEGJ9PghdLRyM1wKPryCUT0hgCet1tmC5vAI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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