SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9b47f81fd53934dc6734a90acc8b26571d67433990c3b49cfb03ae997daeca13' 
  AND token = 'TL7GQbDTlCiaOM0OiMl2iskkwFAJ0U8YEKl3PiGBfG8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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