SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd8ce54df4e6831b6e84db76ffbab6a380c257fb0ee73ed5506b61837a074100f' 
  AND token = 'jT/NAMmFDZ6J5tduEewC6gEbDqHWv2L6vmK2/bVGP8Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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