SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8e385054a9a2f102a5e70ffe7f98fb44200cc4bb6022c64c9add91192f952b8a' 
  AND token = 'm3PC3p+0jK7kzebTgzhvuj44GgGPFowaYHIh6YFdSYQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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