SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7183dbcb857e372dd5cf022cafe44f13cebe0dcc367fab9b1382f7f4e13e6fa3' 
  AND token = '83seq+1ynSZHrfnUPLGgX29pmlLsTeGPF+0kAyE/1fw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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