SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '171a01b4770886e2b1c6f138cfadd3de664dd52c3a71ad86721db75f6784c34d' 
  AND token = 'lp9ECjN9m09ToafdUVZ+etPD1q6FTjIXxVIJ0sAmPXw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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