SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bebbc34da0e8d0ec6e842592a00939e1f701ac84107176303718a02409788ccd' 
  AND token = 'R2YvWEg6DXmWEcrsRvvk4gn+vlqk8aEOjiltrXgfCrQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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