SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f8e17167b25203c4b8bd07604d61390e3290e30d065559aa1b5c8eae167d436b' 
  AND token = 'MYE+IUwQGSOADLnUXakSeH/OBFFV5aERrek2BBI3gBM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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