SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f3e5edbbd70f53d9cc644b0e3b463b4074667e1cd0915cbd8a479d0f37898721' 
  AND token = 'z5vlnTDddvvaG7UXoYLqeHLYq1OKB6m0chXwcwHPapk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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