SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ca0bb5fad3ab6fae07edb1a0308e0ebc785cdefde79e643e561022cf7566e764' 
  AND token = 'b5d/UNoDsTY8pF6Nub74SnEAMzmNBrZiAbfEFI9NnwI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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