SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9b82fce1b5836c83b6b45165d56db961e2f2dd83283c5598a27229d27f178db7' 
  AND token = 'wCoT615KEsTGyhPZBMEYJz74q1mFj7YDEANhqAt+x/U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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