SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4c0a5126e3a6f8640551fbadffdfaa9a0d6f08cc5bbfbc1bab99b1ac4368de57' 
  AND token = 'YP7UCrzFhOSC55P2qF8bDWq0Hr2bDg7xm/PjtBIKKZA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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