SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '92a9ded98e7646b70e820a4afbf58de1ef50b2d2e0d9d95c79d17ddbdd70a697' 
  AND token = '4JDKlU+g8or1F7q+apxpuU80D/JUA69aDQBdvh6fW7M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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