SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '495c4f0602b29fdc6660be72b152a1f0b91ff9754a59996dcb7c0f3f258de2aa' 
  AND token = '6mCEkOQTA78w1AJme9+RhkUdNujnJy1QUv2KHQM+zEI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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