SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '95d70c50f2ddfe84538289e7f221432ed6e2cd8c4e6b9fe93e5b9f7425446bdc' 
  AND token = 'Gr5w3HvS8EYj1nJlXVZyOfNdfuI/wuEKdsBnMD2rjng=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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