SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'efa5a514fbdc5a3b6a1b85295ead866fe55039fdf6f8039e82405058cd6b1aee' 
  AND token = 'f0pnKJQLWSI3G+Y1QvbvrrJ35WJ4EiGARh9RqnGx7F0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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