SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4b1da454181741767551e052b20b8baa992531a78063926c5dfc86bdd7d69d2f' 
  AND token = 'AZvwVPVueTdpyb5PJsCL4JSyeQMhK+ts9RvndNx3jpg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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