SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7b944d40ddd31cf92719200f69ad7df90ae50685e64c5650966e0619c24b117c' 
  AND token = 'bInrKLQq8TYSDj2keHh+xaYSeO7/OOoFBJzCBL4Wo7A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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