SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6ac639f3ffeb25fb32ab5cd8b713d36f2dd9b6521d8280c2b5c0fd413a1b8bac' 
  AND token = 'a47ow0qye+PzC5PCFYxjpE+/Vr45Gvu0AOI0QZYPMCc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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