SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '74fd0326b577ac32e1d0833bdc9011c2eaa49ac26b2f32f59fa40e80d2db48d0' 
  AND token = 'aJNYvculTjKOuU9G+1hkvbEh7pV5gkQ5djXfVSOHLuc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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