SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f67f0209186367bc0fee0d9eecb30953da0af8d07cff8ba82c8a186a7ebcabfc' 
  AND token = 'ZQ6PpnTnWl3BZHI2DAZDcdllJ8qFgfZgoCegQPP0axI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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