SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2763ffb36167314a75d279c951c252bea5590aad0fa0efaee86f5d09788ff7ff' 
  AND token = 'Mg78xOtKG0xZX2NIfvA4FGFnVIYS8OvCT7/xMT8/nIU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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