SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '06c764fbb9f8a0caea0b57ea7b9c33fb0617ec58b964082f4aad4370064426d3' 
  AND token = '5WwlomIUL1pgkAvz0zXM1f9YvTJ9wl/YoQHW2CBtBus=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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