SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '695bc0f38435d739d784b2ca0a2c516d771f8cae916ddfc629654781d2cf755c' 
  AND token = 'e7oVmyLrnNPtx/yfsrQwmYJrm8nteHoVY4KHeu2+8N8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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