SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6cb6ca37d874f299bb119414d418c49947e953d6bdf069803396f46b38ca2915' 
  AND token = '1OxctjStQPmYsd+J+HLiI9YPD8AuaTpo/CM8Kzsr3JY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00121

JSON explain

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