SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f4c5b03e4cd43c495a1c5a4023b7e82ee656f8e7486fea0a729da85f0748677' 
  AND token = 'wgsYKUAZWd4qdHrC+LYwCdUjtEuu1yWYOsvvbYjzQhw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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