Sandbox

SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'eff4b6fc135fdc4efb1aafaacfac19a2a005090d3f6f722ad3dd3c3d53d51790' 
  AND token = 'KcsEdZqtxy6a5cmu0zr/mJrIMe9mzFxGbmRPRkaTJNI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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