SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3297bacf6382d2a7f47ab347552c4f7d2f6fa485812e72f7000398743998bbe3' 
  AND token = '2JBpr5MfnjOPzLvrTWm2zQdZEqGNGdqOt/kvwV2YYbM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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