SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f1f915b2c802258bafb7643523ab88eafe82cb0e0b9d603e607911069bad1d02' 
  AND token = 'Qz4r3pH/GX0+0qvWou3KVLYfz9afAZwquMldH0nCqIo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00066

JSON explain

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