SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '14a1fcccd639d25880442255c7bef763b735e57c4cda421b3345edf56de55ff4' 
  AND token = 'XHjieQlpZfxtq3/VbYIhEaaLNtUgoFXz2vsWBOerOTo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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