SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '28a450ccfd53b1a8d30bc2d1b6dcbfcddf409f9cf4223ea500cc44d4f9b8d507' 
  AND token = 'PY4Phyo9UyxosAq5r11lKhaUUp8UxLZije5O7Qjii4k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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