SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2219a078c03ca183f73e8251eb55b08c5d9c84fb6e745c698a9691fc78d1c689' 
  AND token = 'ksOR38V8YwIULQbGhV1euIvgq/UXZN7rsdKoj6UhnMc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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