SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f93d3a5789ab92453e3996994572f237fbdf2690e30c26982da58d1c44e78e08' 
  AND token = 'Szh/ikspsf9TcMUcXlfTgxvEKQfEm8/bCitM52rIT8w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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