SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '698a285d23a92b2cce7667ff72697f3edce44b5c78d6de5fd2e011b17a05f8ea' 
  AND token = 'fsfNdJH+L30nk84+0BCjvAJSsGKhPVLiTqKO+3amJwg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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