SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b74f52b7315594366053192b22e65af3811f290b2941c5efea63e024588fc277' 
  AND token = 'iR7VtfFgmLXe7p0vywCc/v0DDk+RF1BGU1AZxw4rUTw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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