SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3fccdc29e6e36e9d6e5e6cbd1625beaced524d6dafb8d29ce18854e525320610' 
  AND token = 'MWO9uQ1w3WouyDL4jl4gDXzKyAzK7SH6nPAIXvqY97M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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