SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cecc0426f124640e35725136daa3aca35c85c611de808c913d2bbe6023390dce' 
  AND token = 'kVMUr2OHtfU/SRMgIJM9p+h0UJRtbcqDzmjXkp4Hp+o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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