SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '45dddeab3bf885445f5fc7e003391af33d8289f90e3002629217eb64c415ad36' 
  AND token = 'UFouWFszuRsMBvUzJ4JrMAOkufOxVYYB2S4P4sVq+xY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00056

JSON explain

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