SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f5b2f357f34c267dd95662d380a2e30808517f6e0206efa05bdad17079198bd8' 
  AND token = '8zDoRPCSn3onWfFPO4UI/hAPt46jWuK1z56f+A+LwoI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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