SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '12617b145ddf78c800c7cca55f04163610ab356c5b900753fefe36a1e7c0f223' 
  AND token = 'I3V82sYopyf2hbLB4mY1SDwRk6wnUCcxM3Ijb+UhSKU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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