SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4b1b62e45c279cc48555d6aee49fe92c320fbda4fefe6ca1dad637fbb35fc381' 
  AND token = 'yFVP/Wjl4AHXYKW1GlQF/HdRZQEFga9Y9NWS9P/qKuQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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