SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '60caec574652317fdefaa786a1c2a139b5f400b4e84560695557c2e1c2708d7d' 
  AND token = 'JKD/5vLaafSle+VQLIeV/75XcsO0kDUA5D1QmwtlAJY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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