SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '15ad41bd274b56794bd1bfbae2c6cf60296262af694cb5b2c2a0035fbc93611d' 
  AND token = 'GtYoWnoZPrEKoeVSt0Cbl7gkjPO4QzRHnCCUqAQ2Wxs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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