SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bfccaf8e74cf1fb6dffc9d4db50d169817a75ee4937caa5cbd685a4407d7e2a4' 
  AND token = 'HJ37z/lpwo0evRelCQz6w2Pt6ejSINNrY+xLPQg8LwU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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