SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f4c405051a33efdcfd8762a4bb3195faf1d7bfabff2bf78eab26df1280fb122b' 
  AND token = 'ltpFK3C3iTGX92KIC6DweD/5pxI2gkFb+ojcQUEKBjY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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