SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '5255b59e5032c152d4342e67cb0730e5ed386987de52cdd110585af009da3628' 
  AND token = 'KMmAc9gcNZguPo1LPR1dm8pSbJCbGGw42/Q0LPCxQLY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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