SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bd5e2c7a036c5c8d770b8d33140b03643346acf3d06a959da2ac1fa4a02768cc' 
  AND token = 'Vl+5SYlpOPGwxBum+clqkWmwJzVvXNtsM40s12Ls/9c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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