SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd5c8c30b393b31fe3cc994c11e352e3df75d3f2ed11f492109a25ba50ceed05a' 
  AND token = '7DklieuQDxnxCuFUAqjv/4HcmmZVXFqtGibDcsQmHns=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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