SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ffe69a20af38e8ae8825307895617b8a6868bc5a9a2551a8126c27d8019923a2' 
  AND token = 'ggaFj0l9uhxLCvGaqDg0OYeY2T125xiTX6HVGbA3wWQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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