SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eaec4e8bac3c3bba50887c10cbd8700bc0152ee807f4195b39d7b412c8a3c8b0' 
  AND token = 'IWoV7+mtI/5H2HqHdiKYktwHdyysg033GDCkfI4hTBc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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