SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d9e624779fa28a1b5fa0b34f914e7f863a1a53345f19d0a76b4adf05d7696b6' 
  AND token = 'SvxavsJ9qi/zZY7azjwitKHvPRXZGXUIIAKy2oNm8VI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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