SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f63ba7ee3593e77758969a6e0bd8b696e168afd89733931df819f7eebed1f97' 
  AND token = 'hYOUQki/tTOyibfr0zJtoGBsTv8tnQbFprrb4GYZ8Nc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}