SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1d9a850af876af8321a6988e3f848e8f6b022a488da891baffc88ecee347261e' 
  AND token = 'KcThCROTbFcUHGyFhzlqwRJTmNnhd6hjG4JXkT3mRoc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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