SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd1bcf6209fb4d8b6313b270d2f5d51dc8fcc221f6475c76833c66a39f010ea1c' 
  AND token = 'SRxPUgYVvYk1yKL7GG9RHqkeoeTyX4IplmrVl1/7BU8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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