SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dba43738d262d9840a47dccfb592d52b8ab9acae213348f37cc9bcdc76f56621' 
  AND token = '4h5yMtgcFwqmkUTeWKYYX5f7yZt9MYhnDAxy07lvmAY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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