SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '39bbde037e6d564e8b105ba8ce7561c76bef66ff816faa715f6aa25c5cfea70a' 
  AND token = 'bo/7hsuPFGJTtDBhF5zdQ+d2b0KXXg/peoPZCPJlOCI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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