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SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '9244c4d13cea85909b5fb9fad5063b8c916d2bf5e039cf6b6831b7e0e5fb460d' 
  AND token = 'kpVaUsdBpf5RcyP7QQp9CtQ4GKNw28Xn6Z8BAlE2DvY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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