SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9344ecf90e11816042684a62749b15c84db4e36aebdbce1c5bfd1a4309e5ce64' 
  AND token = 'vqppjNpKTCH5CZPvzGEFFoZ1q4g1fE+mwrKJMEH7+kQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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