SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aef9088116507764d7a521a81c062d73e8b532d2f26581b8bc7de82914accefa' 
  AND token = 'K1XZv83Jv9BvBhxYn0is4FLzvSkjKT/BpZjfF1gQYRE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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