SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4febd78f77a34501fa0f6a97aba041d6b6feee38459748cabf0f836afd3b4930' 
  AND token = 'RyHc3YoETTFE3uFyTh4lYhaoj4O8YcDO53AbdLdduwI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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