SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1a5d560935605006bce646138c561ed5829efd3b79b4f15365bdd5c8a1ca89f7' 
  AND token = '/xepzVWK5yGyQO6GTpkZPBGn6mYtv4Xd/1aZjeEhDN8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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