SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '80dc498b2e6cf6aed86969c3915aaac46783877332bdc7b0a75a868ec10f818e' 
  AND token = 'RxsDfEg5HuBHZTsBAB5doaai+oLBEWsAlAPVpGnsQps=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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