SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '13a19fb77b522949e5cd055eec9c9cd8665806190171dafbed690eb61e3818be' 
  AND token = 'zaJtGoKeJUNFKRqu4cP+LoomvKUobHyGdpkCrvts9tY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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