SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5fbea2bbc42faf4e9a9839acc1e681d5dffc243ae674313de5e22bfb57394623' 
  AND token = 'ljLiUqDg5oPiRhf9w/07vCnDiVd1+ozgNqFVevf0pNU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00079

JSON explain

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