SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'beebaa65561d3ed712595b5194ba78f31677daaeee03edbbec1debcb39d450b0' 
  AND token = 'x31meck8ui/8HAsRSzf5HdbEQePRoYGUdyBZSa8kDVY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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