SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '930874b3db614f87d14e306e149c6959c650bb10e6894ade0958df667048dc17' 
  AND token = 'jAh75SZyluBX16VzO5WDBWGBSsnfKJ83zkhU677ncNQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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