SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'da3eabe1e4608a914be615cd48a88a3624a1a41d6ea8c47efdc0a82b684996ad' 
  AND token = 'QUO4AOc7RfjcwQAuNRtGuqjc+eLYXyvQp8GAMQKBqHU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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