SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '20bc63ca59af1d8c9cf4e1dbbb0788439b373126b15ffd0be60963ebc805b928' 
  AND token = 'OZvMVuN+jMzrARfnXv+tB1pmk6hV5Ub/vqxaNg0ooHI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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