SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5420d6a5c98ac57a365d59c0a396c0d63f8e9d5e673ae22abf019dcbd109cab5' 
  AND token = 'FHyxclrmmEpQtbtEbYEY/ghsGBQi6XTVMyAcXkKFNmc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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