SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3fa3cf749202d92bd6362bdeb7aa264de747b1a8665c690cc4cbff9b2fc2d1fb' 
  AND token = '/J4FITV0pGyIw9SMKKd4ChnzOtb44V0pchiXbW6b8Xc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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