SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd941d2f18ca88d5501fadc29dd479abd68147e99ef168c04c0869f6a58f62262' 
  AND token = 'MJEtFAwqF8B1gqEdP4hIDnzpAMm6KH1ea8p6NVGJOu0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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