SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '5fd71d85f2d5a44883079b4f05534f79b3546f8bb7e149e2ebfd675356e8a9a0' 
  AND token = 'gz/PlUh4hZL4UwGdC3UdM7ix7ERA2obWAEQLI1WgQI0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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