SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9649e5e2cc9adf92ed26449d2c44885272e0a0503cb1fd7843e94d437a1af5a6' 
  AND token = 'nAohCv2Rg5/v39cD/bxseJYpHI0RuC7ndSTGYVAfdOQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00064

JSON explain

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