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SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd342e29ff9b7723cb2dc4bb258833c4ba48b5348349a04c3c54e33d557d806d0' 
  AND token = 'fJTRzNc2VAmTCiRPZiWs1B5bJ3O6wVrvh/2i7C6DFyA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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