SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec20cf96d16f6d15d91fdeb88b063b27160ee455c4dd368b5e4ad72e032fb999' 
  AND token = '+bV0t81lZNKctwxXGC/JOM1zLM+xv4RHgfH1B+nLo+I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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