SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1e64b4cf24704622419df7a9c68df184886a94ca072044477b40621ce55c94e6' 
  AND token = 'r/rjgFcVn33JGLSQIiu/kOKMroPEhJcMss1Z0vKZPjU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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