SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c75c2ab4f055812315f7a358ed196529a498423a4af106990dcd4986ef1e9c6' 
  AND token = 'zECtW8g9T7YcXq8k5FXQ+Anqbb9KNvrUiCGRHI7nV2g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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