SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5c8e6b4098231c163c942440b69e9cee1af26bb670d67f2ce70c285384f141d4' 
  AND token = 'pqLJnKcVFUe6u0bUzSZx0xV6E+50gYW0Wl5BiXKZjqw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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