SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3c9e131d6b5a48bf177a1ebf5e47890bb0dee33c41d49dfd2a9a3dc78e9fbb8b' 
  AND token = 'NJj2VpOvha4K21YP4ml+BZNHQXmVO7RmL5tu3vqFc60=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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