SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '340c26540f9c3a324cf85df84dd42f3b8ca2f601cbebbad489fc572c857f8ed0' 
  AND token = 'uSF2PPp/dKelKXs72JMGhUcit8g7vunam6FXBXfasMc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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