SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd5634cc0f51faff27c1848e2cb87f1bcf6684dfc0282a0916c6e0b51166771ae' 
  AND token = 'zErjvyAaGxz2q4CYVtYbSgOLkyzu8LvCJwM4vFj8k6A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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