SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a8576a07b2edac5f22dc020077b4f3cdca2a10883472cf58a65b55c1ce94aec6' 
  AND token = 'yEDTyDwzdTQBDY0DZvYnpXTVbBlKSU4vY8KC90hpYBY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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