SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '35de28b23af0f877071e5bd982b68b404dc33e176833fa83c6e7ce0964bdaee7' 
  AND token = 'JoFYQslVAPBf30bEg74Ng5EVdFoj53gFzA+JQ4CR7JM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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