SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'debd54769db0b922de797353e1450f59a2034cdcebf26837cbc7e81dc8459ebc' 
  AND token = 'fs18BvopUOL1jM9rvuLmTIg16H281wiwBwo/6cLouuM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}