SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e339efc648e695b65336d8dc5e47936d33bdc57cd8875288c639832ca74fa0e4' 
  AND token = 'zNhRyi/0IoG+YMjwMkJ4IbRzrRQtSwOVQPMPYpUtJ2k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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