SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f0b48a37e0b8332f765e7cc3ad46cc94889b3a38390f5e40287c17e7d7d66b76' 
  AND token = 'VuVhuXHVZ/SEWunGmL9J3u9HP12EroLRXRZB6in+RUg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}