SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f2dce092001d365260af3786b90d220009d583a9ceb3c8c13e1becd6971791ea' 
  AND token = 'COa4j/ZnqHMXcoELKZQTiv54/N2DZBux9fjBB8n50/w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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