SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ca9966c64e3978824871159dc57bb97e65ebd42162790f5291a336c69bc28f0c' 
  AND token = 'qMOeqFfDVVXUfqAxscdZbdzgUjcPTrnJ5j2iRGGY/Cw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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