SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '642b4b16b497679097ddad07409dd3162fd47e0bc8cc3258b1b6931587255e9e' 
  AND token = '+BcQZLo74PJRwhp6eUeQVLQ0vrYVGm+VI6cjCLJ9wuY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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