SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'abba2032239019bffe4f8bf3514fd29d59c371ba8a0b3d3d007ec78ba54f16f1' 
  AND token = 'NSek0VUZz45hMSw64hXaQ3cUJv7LZloBKDww5TvNPxQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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