SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6a9b5cad60d902d6916d6d7c912494555fd67148b55cbf9106217eccf88b78cd' 
  AND token = 'W5vx1RNWHattVOB7HmS/bwiIxAB2e9rL4RskKneF5Bk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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