SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ac1c64a978e05a555f8e69eb0546979ceef953970faf3a4352e7eff6a1e07370' 
  AND token = 'X/7hhvorGexywmP3IhLikaHcVFOX0fvTg8JmO3K+1hA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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