SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e53138f0175b75d3f995496735526532b20c7219d1297ae588707ddc7df30782' 
  AND token = 'podWhUFHs/Y/jzCLgqR9zTUfxuZzh2PWN9ThXtLJvqI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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