SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0dc1397bb7f071fb2ec453cb45119448eeb1498b753bfad18a6ee6429f8b8c98' 
  AND token = 'WuhqE/nIp45SmAfCImCk5o2pFoI4SlJeCwpzoxEO/9g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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