SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7a5a19ba5c816ef2add3c1565d3173cb962bc23b8585582322b61549dd04cc40' 
  AND token = 'Ca/VLjQq++nJ/wtRLzTVFwwC5l2A9d9wBtq/mxYN9fQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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