SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec45e4993b66619dfb7c7506ca8efceac1886879d86363093fec92f5dabd4812' 
  AND token = 'xaBEbcIzsfqDNpKZAtS/5VQT6DuuawEK8egY0xFocIQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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