SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c09de24dd5fb8245a40728675329dd265767b12f86bfa4f8d20375429f97ec15' 
  AND token = 'UwgqDX9fsZznlKd7IWug3uHWDz+95TnrSPkqeT6DGQM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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