SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e283b11fc01ae7c80a2d6264431e5668361132161a398e7272a35a663f46de33' 
  AND token = 'swfcVSCQs9jZ2a3E2VGGNFEvOArMYSS6b3VvUF/cQi8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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