SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '43d3d6b0b1cce3ac56fd8c82825138438dd5bf946e4091fe6db29557b1089f60' 
  AND token = 'AVJOI+BkPEOtjqGpChY21bspO/t7DiAYVBIvgE9pUWw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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