SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '84d884a7fd91626f8f06be395fcfca89dc163348ef0ee1de36bfa7a8ce729037' 
  AND token = 'DViHCQ4+bRJ5AAaBodIOOsYJ/KufG8RnHxtIlQm+xtU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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