SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5908dcc7f3b088672fcbf6eca799f41b0fcc5507cb0697426a789f995416b589' 
  AND token = 'cdpFUj95XjT7fTyiXjU6DpoJwRljzWjKaqvVGwbGwbE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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