SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd98a9dd7b489db5fd3d3387025eb7510c07d4b047b0486fce146b6ebc10c34fd' 
  AND token = 'JeaKdZZIWIjQXivx3vUVFO+UhwFSy8ITqSa+7OIqaWg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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