SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aaaef5d36c624e651c81f00dec85af382509e95e543fbdcbf194bef870649811' 
  AND token = '2rZ6tmkgkYBSj/ijr8fwdvKHNeFFaOAti57xkO6INok=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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