SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e53c6876991bd0d60aeb2aba94f329e050159c8519092ba9ad895f36c54cf4da' 
  AND token = 'RNUV0JHvR2YRnC4n0cJ/jd8M09hN8bB+wIoIBDsZ180=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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