SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a2d741d0ea17d560cc21105a1fecbad24f36e4ff72125061360608848f88d33a' 
  AND token = 'jnDkMszmfqtuSnSJvhEXBnHA/oGR+49MKocEIqTFVJY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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