SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '62f77b67cc52dd0e924066cb1f39760b3c7ac2b31e599f994a2713bc97e22dd2' 
  AND token = 'nkVJo+lxtJjCRqQYAdrsJflBM/u7AUzvW6jgnrrlW84=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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