SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7710fa192ef5636020e1e1962c7b093731cc658e884bccad43a84c87a2882359' 
  AND token = 'v+A3CHrm6XZGPxMAPrkInzfRjjXJtOa5PQQhBvrunB4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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