SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '19b331e9d323b743e1d94ad414c48bab0288515806f365e38613f424c9a1d8fa' 
  AND token = 'Jo2Px/LQ0Vg+OzmnutVfq0JcOpMOc2rnMzhePEF/qKQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}