SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c3088a34897bc4cafd0513309d61b98809601fa7c0c36129f3bc6fef0b366a6c' 
  AND token = 'wogCxn3johgGx4pJoGFPSAaODvuur2SMkup8zQZ+Xwg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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