SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5813eab5615329800402a447f6e31eeb703296a38adee682361f5ef5a48a934d' 
  AND token = 'YT5oFtVwt9U3Vyos756sAF28/pcC6uH6x1WSBOOgAv0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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