SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5700a8df5f8edadff2a70952c52ff1ecb4014c7b56f4363a1abaab46d047a033' 
  AND token = 'aYcYrsNO9oPRc28lTRJMfe19TfkCaE9zG1TTf3PExQw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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