SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '9cdf98099dce43510197821e75cbe4ca7f3cf04b29ad698c63d3e092e8319b5b' 
  AND token = 'H97pBF8Gj8Hug/DbXGL0/I3KU9p69kWmRVLQ+tI1kQw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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