SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '97a0c80cc67b96e9c196544558ccee0380d71880185c1894ec1b58ad77f0309f' 
  AND token = 'nIZLQvaUCF9ZAzF1tcJC81l1xvgb0uX/A4bcE4pm43g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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