SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8465e12d21c129c8727e556150f6511f0f5f009e4573b92bd10e8b117314df74' 
  AND token = 'y538Up5VF7KlJRo0yjL59gER1ghOEeDQ0vVI4BUybvk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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