SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f4cab7694636bc399a5baecc6572d0ed77abfb0d720d7a0cb84bcc699545184' 
  AND token = 'Bzd192ob7LIpWxly5ULpE939KjxeAACgHvS8BksMFWk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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