SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '654c765abc714e9d8227bcbf0625b398ba2c14459b3acfc8b04085cd1b1035ec' 
  AND token = 'G6XDCRfGuvOSM6VZ2hC/wVFscc8K+IBIuHF7f12Z5Wg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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