SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3198af10db191fc83a604beea9d3436bdca9e69d5b984f31e6311b331bac767a' 
  AND token = 'OLs+aRHGYP6EkWmyFYizP4F6Q1+KuhGfmagONa1lsic=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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