SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b705f5885f8b9b9dd746d352221669af39ad22e6d8dae61f94d34ab7ef99f631' 
  AND token = 'HmUYNZKXNUup8GST0zkd/UK2iRfwywseP7JOmDg6CcE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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