SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e1ee6836eacf50c098fdadc10df4f3e27e87577685f9287a7f1316a55588a189' 
  AND token = 'OH6WhvJRM9RZtcqXdvJwpMUfxd0dvEDhGK6Je1zlGM4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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