SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8c93e02bab736fd70a8b6c3afe20d988bd71092ff9141ceefbd015086330ef8d' 
  AND token = '3njfmuiWsv5vV1UcbDV91oSVkwEUpJbaVLVac/h6Je8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}