SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '21346d429b9e87809ba666b45e871f3740817c8f1d44eea5221bfac9de8e80f4' 
  AND token = 'BFWJZpEu+cLWOn9UZd1A2gCfY6Xf/frA2fuszaUwhGo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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