SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3a3cd9ffbeb95dd2e22d751d30824840174171acded462ceff93642b391d5265' 
  AND token = 'QLEwRHAdoTLB48ydbVQ9P2NVHSojWukkZho08a/LXRU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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