SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9521a0b7f17fbaf18ae1d924a0057f440faf091194a63d5e2332234607e3100c' 
  AND token = '5urJGpY8hoNg9yZlCdCAptdtjYqg4x6AnvLLwXicpCU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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