SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e5d89306760cd2c261d9749b9fa9acaa6c29190caebd722daa8d259017e70043' 
  AND token = '8buJGJ2ZOgltma/SAHNbcLolZzTwLKHS1EQuoYtiK4A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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