SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0306f90b24645474a70830a9d57c22c086ba02c003d175d95b2effbd4e59a90e' 
  AND token = 'DLPhR5JZOU1Rb0BjnfxR6YWb7gJg12LQfnbaAG/vXKU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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