Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a559451617ef5774bb4854ce8baea59afe0230c9e72cfce2a37f47cc7348ce5a' 
  AND token = '4aS0+2ZiBE9WlLADGTfIH37qmaMMJmy+XT52RLJ3Ajk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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