SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '65520fd747fcf65b12394dd0767369c4aa1dcdaddd9af7791babdf24dc6d985f' 
  AND token = 'r0hgFHTMpolO1edTau9FrNO32dzuQumQcovKwl+YqOE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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