SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5449b522907482cf4fca3529b87e5437058a97df40d2511228febb42b341773b' 
  AND token = '1XZePVbcsXRzn0Zri0X2n5Tp1xcwNMBT1FCPfZgabUk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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