SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '689b8ad3546d12f46341d7e97f6365c0f94868d708296a9a23e5e41899ab2e08' 
  AND token = 'K0yYVYWP34iuG0JEu/WiIKpuKe5ZpVKpuMkmlKU9U2A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00099

JSON explain

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