SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd5773e3979567b7bf2fb58d3087eb335a84dbcba4e6da148e8f32187e59ccac8' 
  AND token = 'mdorsOIOsevAWE2PmYqK/XZTJIejUO9rCQgBch9m8iw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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