SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e5718acb3a0589d3ae3a85b43556e0085f4b652620b4583c2791503fbb9aeb07' 
  AND token = 'mO7GSq9SRVAQYMC9BnllIjfvy0MVB46qcZbBvYo0Mco=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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