SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2ce27560a3786c1cbc7f109685444fdfcff6f5231f6fc958d7ee84a0a1d5f513' 
  AND token = 'JVgDZSEmvVR23EpHn63/o2KsYVcjcMpHihdOJjdmjQA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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